In imaging systems, for example adapted for X-ray, the sensor device comprises an array of sensing areas, for sensing a photon impact. The impact of a photon causes a variation of a physical magnitude, for instance the charge or the voltage of a sensing area. In single photon counting sensing devices, each impinging photon is counted and allocated to the area on which it impacted. However, for sensing device with high resolution, and where the pixel pitch is similar to or smaller than the sensor device thickness, the energy deposited by the impinging photon is shared by a plurality of sensing areas. Consequently, the variation of physical magnitude of the impact center sensing area is not exactly representative of the energy of the impinging photon. For example, the spectrum resulting of this sensing device is erroneous and does not correspond to the actual X-ray emission received by the sensing device.
Moreover, a single X-ray photon impinging in the vicinity of the edge of a sensing area could be detected as two incoming photons with only half energy.